The use of microwave ovens with flammable liquids

As microwave-assisted reactions become more common in the laboratory, numerous incidents involving fires and explosions have been reported, especially when domestic microwave ovens are used to heat flammable liquids. An evaluation of this emerging technology is necessary to assess the adequacy of the control measures that are currently in place to protect the laboratory worker from exposure to hazardous materials and unsafe work practices. In this report, the unique chemistry associated with microwave heating effects are summarized, the advantages of laboratory microwave ovens over domestic models are categorized, the applicable “Green Chemistry” attributes are discussed, and the risks associated with heating a flammable liquid in a domestic microwave oven are examined. Chemical reactions that involve heating flammable liquids in domestic microwave ovens present unacceptable risks. Scientists seeking to advance the state-of-the-art in chemistry by exploiting the unusual effects that microwave-assisted reactions offer should do so using laboratory-grade microwave ovens that possess requisite safety features. Documentation and publication of unanticipated events that result from relatively common occurrences will decrease risk associated with microwave-assisted reactions with flammable liquids.